Multiple choice

A sum of money become 9 times in 24 years at compund interest. Find the time in which it will become 27 time of itself. एक धनराशि चक्रवृद्धि ब्याज की दर से 24 वर्षों में 9 गुनी हो जती है। वह समय बताइये जिसमें वह धनराशि स्वयं की 27 गुनी हो जाए।

  1. 30 year\वर्ष

  2. 48 year\वर्ष

  3. 36 year\वर्ष

  4. 72 year\वर्ष
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Amount becomes 9 times in 24 years, so 3 squarings of (1+r) occur: (1+r)²⁴ = 9. Since 9 = 3², we get (1+r)²⁴ = 3², meaning (1+r)¹² = 3. For 27 times: (1+r)^t = 27 = 3³. Since (1+r)¹² = 3, we need 3 such periods: t = 3 × 12 = 36 years. Option C is correct.

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